(a) Field of the Invention
The manufacturing method for seamless manmade leather ball of the invention is mainly disclosed to allow an inflatable ball bladder having a peripherally wrapped around binding yarn or cloth thereon to form a reinforcement layer to be formed to a seamless ball with a simulated leather surface, wherein its manufacturing method is mainly that composites such as soft bioplastic resin or manmade leather, etc are injected, extruded or hot compressed to form hemisphere shaped upper half bowl type thin cover and lower half bowl type thin cover to completely matchingly sleeve and sphere the corresponding ball bladder. Subsequently, said ball bladder enclosed by bowl type thin covers being put into the one step or two steps hemisphere shaped bowl type upper and lower matching curing molds is pressingly combined under the pressure of the same spherical shape and size and the high temperature curing condition suitable for resin compound softening or for foaming or not foaming resin compound, thereby allowing resin compound softening to fusionly paste with reinforcement layer on the peripheral outside of said ball bladder to become an initial blank with waterproof layer. Said initial blank while still hot can be put in another set of semi-spherical shaped bowl type upper and lower matching forming molds to be pressingly combined and cooled down to a fixed form, and various convex lines pre-made on the inside surfaces of forming molds form ball face pre-forming lines such as block shapes or seam lines on the peripheral surface of the initial blank, thereby forming a seamless base body. Next, surface of said base body is further cortex layer treated or is further put in the forming molds for pressingly combination by pre-made lines thereby allowing said ball body to appear an excellent simulated leather ball outlook.
(b) Description of the Prior Art
Inflated ball structures meeting the requirements for strong impact bearing, smooth rolling and roundness are usually made to a leather ball with ball cortex layer made by manual sewing, machine sewing, or piecewise pasted, as well as a true leather or a manmade leather sheet, wherein most of them are used in formal spots competitions such as foot ball games. However, due to complexity of processing cortex layer and precision requirement for said kinds of balls, besides of the major imperfections such as the incapability to effectively promote production and high price, the other disadvantages such as outlook defects such as degumming, drops off due to leather pasting method as well as poor waterproofing defects due to manual and machine sewing methods have caused rising demands and applicability in manmade leather balls with cheaper manufacturing costs.
In the conventional manufacturing method for manmade leather ball, the planetary leather or cloth is cut to pieces for separately pasting on or manually sewing, machine sewing on the outside of ball bladder ready to be inflated to a ball shape for use as the outer skin of the ball so as to form a ball with leather feeling and outlook. Nonetheless, conventional methods are mainly relied on manual pasting and sewing which has numerous processing procedures and complicated and have the imperfections to produce bad or non-uniform products. Especially there is a high waste ratio in the method of cutting pieces, hence regarding basic consideration in material cost, it is difficult to achieve economic effectiveness.
In addition, the first part of preparation work in cutting planetary leather or cloth to piecewise shapes as well as the succeeding work of pasting, manual sewing, machine sewing or piecewise printing operations all appear imperfections in processing complexities and unstable qualities causing unevenness on the ball body.
Especially for the spherical connecting outlook of concave seam lines which is normally stressed in true leather balls, the piecewise binding method is difficult to make overall tight closure or neatness on seaming areas, thereby usually causing serious defects in the outlook effect, quality sense, applicability and especially strength of ball structure due to unavoidable human errors by operators.